.app-header{z-index:50;background:var(--color-bg);border-bottom:1px solid var(--color-border-soft,var(--color-border));color:var(--color-text);position:sticky;top:0}.app-header-inner{justify-content:space-between;align-items:center;min-width:0;max-width:1400px;margin:0 auto;padding:18px 24px;display:flex}.app-header-brand{color:var(--color-text);flex-shrink:0;align-items:center;gap:10px;min-width:0;text-decoration:none;display:flex}.app-header-brand.has-back{gap:8px}.app-header-brand-back-icon{color:var(--color-text-secondary);font-size:20px}.app-header-brand-custom-icon{color:var(--color-text-secondary);font-size:18px}.app-header-brand-text{white-space:nowrap;text-overflow:ellipsis;font-size:1.25em;font-weight:800;overflow:hidden}.app-header-controls{align-items:center;gap:16px;min-width:0;display:flex}.desktop-nav{align-items:center;gap:4px;display:flex}.desktop-nav-link{color:var(--color-text-secondary);white-space:nowrap;background:0 0;border:1px solid #0000;border-radius:10px;align-items:center;gap:6px;padding:9px 14px;font-size:.875em;text-decoration:none;transition:color .15s,background .15s,border-color .15s;display:flex}.desktop-nav-link:hover{color:var(--color-text);background:var(--color-surface)}.desktop-nav-link-icon{font-size:16px}.desktop-nav-link.active{color:var(--color-primary);background:var(--color-primary-light);border-color:color-mix(in srgb,var(--color-primary)16%,transparent);font-weight:700}.desktop-controls{align-items:center;gap:10px;display:flex}.header-action-btn{white-space:nowrap;cursor:pointer;border:none;border-radius:12px;align-items:center;gap:6px;min-height:42px;padding:9px 18px;font-size:.875em;font-weight:700;line-height:1.4;text-decoration:none;transition:background .18s,color .18s,box-shadow .18s,transform .12s;display:inline-flex}.header-action-btn i{font-size:15px}.header-action-secondary{color:var(--color-primary);background:var(--color-primary-light);border:1px solid color-mix(in srgb,var(--color-primary)16%,transparent)}.header-action-secondary:hover{background:color-mix(in srgb,var(--color-primary)10%,var(--color-bg));box-shadow:var(--shadow-1)}.header-action-primary{color:#fff;background:var(--color-primary);box-shadow:var(--shadow-1)}.header-action-primary:hover{background:var(--color-primary-dark,var(--color-primary));box-shadow:var(--shadow-2)}.home-link{color:var(--color-text-secondary);align-items:center;gap:6px;font-size:.9375em;font-weight:500;text-decoration:none;display:flex}.home-link i{font-size:16px}.mobile-hamburger{cursor:pointer;color:var(--color-text-secondary);background:0 0;border:none;align-items:center;padding:8px;display:none}.mobile-hamburger i{font-size:22px}.header-mobile-menu{border-bottom:1px solid var(--color-border-soft,var(--color-border));z-index:100;box-shadow:var(--shadow-2);background:var(--color-bg);-webkit-overflow-scrolling:touch;max-height:calc(100dvh - 64px);padding:12px 16px 16px;animation:.2s ease-out slideDown;position:absolute;top:100%;left:0;right:0;overflow-y:auto}@keyframes slideDown{0%{opacity:0;transform:translateY(-10px)}to{opacity:1;transform:translateY(0)}}.mobile-nav-link{min-height:44px;color:var(--color-text);background:0 0;border-radius:8px;align-items:center;gap:10px;padding:12px 8px;font-size:15px;font-weight:400;text-decoration:none;display:flex}.mobile-nav-link-icon{color:var(--color-text-secondary);font-size:18px}.mobile-nav-link.active{color:var(--color-primary);background:var(--color-primary-light);font-weight:700}.mobile-nav-link.active .mobile-nav-link-icon{color:var(--color-primary)}.mobile-menu-divider{background:var(--color-border-soft,var(--color-border));height:1px;margin:8px 0}.mobile-theme-lang-controls{align-items:center;gap:8px;padding:8px 8px 4px;display:flex}.mobile-home-link{color:var(--color-primary);align-items:center;gap:10px;padding:12px 8px;font-size:15px;font-weight:600;text-decoration:none;display:flex}.mobile-home-link i{font-size:18px}.mobile-auth-link{cursor:pointer;width:100%;font:inherit;border:0}.mobile-auth-link.is-login{color:#fff;background:var(--color-primary);box-shadow:none;font-weight:700}.mobile-auth-link.is-login .mobile-nav-link-icon{color:#fff}.mobile-auth-link.is-logout{color:var(--color-text-secondary);background:var(--color-surface)}.back-link{color:var(--color-text-secondary);border:1px solid var(--color-border-soft,var(--color-border));background:var(--color-bg);border-radius:8px;align-items:center;gap:6px;padding:8px 14px;font-size:.875em;font-weight:500;text-decoration:none;transition:background .15s,border-color .15s;display:inline-flex}.back-link:hover{background:var(--color-surface)}.back-link i{font-size:16px}.back-text{display:inline}.lang-toggle-overlay{position:relative}.lang-toggle-btn{cursor:pointer;border:1px solid var(--color-border-soft,var(--color-border));background:var(--color-bg);color:var(--color-text-secondary);border-radius:8px;align-items:center;gap:6px;padding:8px 14px;font-size:.875em;font-weight:500;transition:background .15s;display:flex}.lang-toggle-btn.compact{border-radius:8px;gap:5px;min-width:auto;min-height:34px;padding:4px 10px;font-size:12px}.lang-toggle-icon{font-size:16px}.lang-short{display:none}.lang-full{display:inline}.lang-toggle-caret{opacity:.6;font-size:14px}.lang-dropdown{background:var(--color-bg);border:1px solid var(--color-border-soft,var(--color-border));box-shadow:var(--shadow-2);z-index:100;border-radius:10px;min-width:180px;padding:6px;position:absolute;top:calc(100% + 6px);right:0}.lang-option{color:var(--color-text);background:0 0;border-radius:7px;justify-content:space-between;align-items:center;padding:10px 14px;font-size:.875em;font-weight:400;text-decoration:none;transition:background .1s;display:flex}.lang-option:hover{background:var(--color-surface)}.lang-option.active{color:var(--color-primary);background:var(--color-primary-light);font-weight:600}.lang-option.active:hover{background:var(--color-primary-light)}.lang-option-check{font-size:16px}.theme-toggle-btn{cursor:pointer;border:1px solid var(--color-border-soft,var(--color-border));background:var(--color-bg);color:var(--color-text-secondary);border-radius:8px;align-items:center;gap:6px;padding:8px 14px;font-size:.875em;font-weight:500;transition:background .15s,border-color .15s;display:flex}.theme-toggle-icon{font-size:16px}.theme-toggle-btn.compact{gap:5px;min-width:auto;min-height:34px;padding:4px 10px;font-size:12px}.theme-toggle-btn.compact .theme-toggle-icon{font-size:15px}@media (max-width:768px){.desktop-nav{display:none!important}.mobile-hamburger{display:flex!important}.app-header-inner{gap:10px;padding:16px 18px!important}.hide-on-mobile,.back-text{display:none!important}.header-mobile-menu{padding:8px 16px 16px!important}.header-mobile-menu .lang-dropdown{left:0!important;right:auto!important}.lang-short{display:inline!important}.lang-full{display:none!important}.app-header-brand-text{max-width:min(54vw,320px);font-size:1.35em!important}.app-header-controls{gap:8px!important}.lang-toggle-btn{border-width:1.5px!important;gap:5px!important;padding:7px 12px!important;font-size:.8125em!important}.lang-toggle-icon{font-size:15px!important}.lang-toggle-caret{font-size:13px!important}.theme-toggle-btn{border-width:1.5px!important;gap:5px!important;padding:7px 12px!important;font-size:.8125em!important}.theme-toggle-icon{font-size:15px!important}.back-link{border-width:1.5px!important;padding:7px 12px!important;font-size:.8125em!important}.back-link i{font-size:15px!important}.header-logo-icon{width:36px!important;height:36px!important}.mobile-hamburger i{font-size:26px}}@media (max-width:400px){.app-header-inner{padding:14px!important}.app-header-brand-text{max-width:calc(100vw - 168px);font-size:1.2em!important}.app-header-brand{gap:8px!important}.app-header-controls{gap:6px!important}.lang-toggle-btn,.theme-toggle-btn,.back-link{padding:6px 10px!important;font-size:.8125em!important}.header-logo-icon{width:32px!important;height:32px!important}}@media (min-width:769px){.mobile-hamburger{display:none!important}}@media (max-width:1100px){.desktop-nav{gap:4px}.desktop-nav-link,.lang-toggle-btn,.theme-toggle-btn{padding:7px 12px;font-size:.8125em}.header-action-btn{min-height:38px;padding:7px 14px;font-size:.8125em}}.desktop-controls.keep-on-mobile{align-items:center;gap:10px;display:flex}@media (max-width:768px){.app-header.has-visible-actions .app-header-inner{padding:12px 14px!important}.app-header.has-visible-actions .desktop-controls.keep-on-mobile{flex:none;display:flex!important}.app-header.has-visible-actions .app-header-brand-text{max-width:min(34vw,160px);font-size:1.12em!important}.app-header.has-visible-actions .app-header-controls{gap:6px!important}.practice-header-actions{flex-wrap:nowrap!important;gap:6px!important}.practice-icon-button{justify-content:center;align-items:center;width:38px;min-width:38px;height:38px;min-height:38px;display:inline-flex;padding:0!important}.practice-header-actions .score-display{flex-wrap:nowrap!important;gap:6px!important;font-size:11px!important}.practice-header-actions .score-display span{white-space:nowrap;padding:3px 6px!important}}@media (max-width:400px){.app-header.has-visible-actions .app-header-brand-text{max-width:24vw;font-size:1.02em!important}.app-header.has-visible-actions .header-logo-icon{width:30px!important;height:30px!important}.practice-icon-button{width:36px;min-width:36px;height:36px;min-height:36px}.practice-header-actions .score-display span{padding:3px 5px!important}}